Effect of ambient fuel vapour concentration on the vapour penetration of evaporating n-hexane sprays

Ambient gas properties like pressure, temperature, density etc. play an important role in spray evaporation and hence influence the spray properties like penetration, cone angle and liquid length. The concentration of fuel vapour in the ambient gas was seen to influence the liquid length in an earlier work by the present authors. A method was also reported to study spray parameters at constant pressure, temperature and density but at different fuel vapour concentration in the ambient. In the present paper, the vapour penetration of evaporating n-hexane sprays have been studied by means of a shadowgraph technique at different mass fraction of fuel vapour in the surrounding ambient gas. The results revealed that the ambient vapour concentration has an effect on vapour penetration and cone angle at low ambient densities. But, at higher densities, this effect is absent, although the liquid length is influenced even at higher densities.